#include <sys/time.h>
#include <stdio.h>
#include <unistd.h>

int main() {
    struct timeval start, end;
    gettimeofday(&start, NULL);
    printf("%lu, %lu\n", start.tv_sec, start.tv_usec);
    usleep(1000000);
    gettimeofday(&end, NULL);
    printf("%lu, %lu\n", end.tv_sec, end.tv_usec);
    return 0;
}